OFFLOADING DISK-RELATED TASKS FROM RAID ADAPTER

摘要

A storage system includes a RAID adapter, disk array switches, sub-processors, and hard disk drives (HDDs). A disk-related operation is initiated in the RAID adapter. The RAID adapter dispatches a command to a disk array processor (or sub-processor) in an enclosure for the processor to perform the operation on one or more drives. The adapter may dispatch the command to a processor in a single enclosure through a disk array switch or to processors in multiple enclosures through switches in the upstream enclosures. The adapter is then free to perform other functions. The processor commences the specified operation on one or more selected drives, either sequentially one at a time or sequentially more than one (or all) at a time. Upon completion of the operation, the results are transmitted by the processor and received by the adapter. Thus, by offloading the task to the distributed sub-processors, the burden on the RAID adapter is significantly reduced, system bandwidth usage is reduced, and access to other drives within the enclosure (as well as within other enclosures) may be maintained. Tasks which may be offloaded in such a manner include, but are not limited to, drive firmware updating, drive scrubbing and secure data erasure.